As compared with conventional Liquid Crystal Display (LCD) panels, Organic Light Emitting Diode (OLED) panels have advantages such as fast response speed, good color purity and brightness, high contrast ratio and wide view angle, and thereby have drawn increasingly wide attention from manufactures. However, the OLED panels still have some problems which need to be solved.
OLED panels display images using a pixel matrix. Generally, rows of pixels are coupled to corresponding scan lines. During operation of an OLED panel, a gate driver circuit converts input signals into on/off control signals using shift register units and then applies the on/off control signals to the scan lines for respective rows of pixels on the OLED panel to turn on corresponding rows of pixels.
The shift register units generally include a relatively large number of transistors and need many clock signals for driving. With the development of flat panel display technologies, products with high resolution and narrow bezel have attracted more and more attention. However, the large number of transistors in the shift register units occupy a large wiring area, which is not benefit for increasing effective display area and narrow bezel design. Further, the large number of transistors result in more difficulties and thereby increased costs in manufacturing of shift resister units.